This fast track grant titled, "Photon Counting Detectors for Clinical k-edge CT" will enable DxRay to bring to market a customer-driven improved version of our CdTe-based photon- counting x-ray computed tomography (CT) detector with energy discrimination. These detectors have enabled significant improvements in CT imaging such as reduced patient dose while maintaining excellent image quality, enhanced tissue contrast, and material decomposition capabilities (tissue type identification). The overall goal is to bring to the CT marketplace a photon-counting energy-dispersive x-ray detector with energy discrimination for use in human x-ray CT imaging. So far we have demonstrated a first generation fast photon- counting x-ray imaging array which has a higher maximum output count rate (by more than an order of magnitude) than all others, and the arrays have been used to generate the first patient images to date. This first-generation system is capable of counting at over 5 W 106 counts per second per mm2 (cps/mm2) and has performed clinical scans at up to 300 mA of tube current, demonstrating both reduced dose and improved image quality in neck and abdomen studies. Our x-ray imaging arrays are completely vertically integrated and are compatible with all the existing gantries and x-ray tubes being used clinically. With feedback from our customers we have determined that there are two more performance enhancements required from our detector for the full commercialization of our technology. In the first year we will produce a fully functioning prototype of the second- generation photon-counting CT detector and demonstrate its performance with all the features our customers require. In the second and third year of the project we will, with feedback from our customers, produce the first production runs of the final product, with sufficient numbers of detectors to provide samples to our customers for testing in their clinical systems. This will allow for patient studies to be performed in existing gantries. We expect large commercial success with this product. This is due to the significant improvements to and advantages over existing detectors that our technology provides together with the widespread and increasing use of CT. The x-ray exposure in CT scanning has been of major concern for radiologists and physicists as the number of CT examinations has increased. Therefore, a method which reduces the patient dose in CT examinations will have a significant impact on public health. Our product addresses the need to reduce dose in CT. At the same time, improved tissue differentiation and material-specific identification is needed for better diagnosis. Our product addresses these needs by improving image quality by making use of the energy information contained in the individually counted x-rays at high flux, information that is currently not obtainable with the non photon-counting x-ray imaging arrays currently in use in multi-slice CT systems. PUBLIC HEALTH RELEVANCE: The overall goal of this proposal is to develop a photon counting CT detector with energy binning and read-out that is capable of producing energy resolved CT scan which can deliver less radiation dose and differentiate between tissue types. Photon counting detectors with energy binning can improve CT performance by counting and binning each x-ray detected.